With Labor Day weekend approaching, at least 20,000 passengers on cruise ships have been stranded at sea or sent to ports away from Texas, including some to Miami.

“Obviously it’s been disruptive,” said Jason Schreier, CEO of the Miami-based U.S. headquarters for APRIL Travel Protection, which services more than half a million travel policies a year. “We’ve had a lot of calls. United is the airline with the most issues.”

Weather events such as a hurricane are generally covered by travel insurance, though policy details vary and consumers have had to scramble to make sure they were covered and arrange new plans, he said.

More than 7,500 flights have been canceled since Friday, nearly all as a result of Hurricane Harvey and its aftermath.

Palm Beach Travel president Annie Davis said she checked with clients in Houston, including a family with triplets, just to make sure they were OK. They often travel to South Florida and the Keys, a task made difficult enough by family logistics and the need to arrange that many seats together.

“Now throw a hurricane into the mix,” Davis said. “We certainly understand what that is like here in Florida.”

The initial storm seemed manageable, the family reported, but the rain kept coming, and roads around their community became flooded, she said. They are grateful to be safe at last check, but any travel they undertake soon likely will mean getting to another airport such as in Dallas, she said.

Houston is the second biggest hub for United, with more than 33 million passengers flying through it on the airline every year, or about 91,000 people per day. The airline has offered to waive certain fees related to changing flights in the affected region into September.

“United is continuing to monitor the weather and conditions in Texas, and will make updates and announcements on its Twitter handle @United and on united.com,” an airline statement said.

After United, the airlines with the most cancellations Tuesday were Southwest, ExpressJet, Mesa, Republic and Spirit and American.